International research led by Israelis has discovered the genetic basis for the
serious and sometimes fatal autoimmune skin disease – pemphigus vulgaris – that
is relatively common among Jews and some Arabs.
The team of researchers,
headed by Prof. Eli Sprecher of Tel Aviv Sourasky Medical Center, worked
together with Prof. Ibrahim Saleh of the University of Luebeck in Germany. The
research, just published in the Journal of Investigative Dermatology, showed
that variations in the gene ST16 influence the genetic tendency of Jews and
Egyptians to develop the disease.
Pemphigus vulgaris is exhibited by
blistering and sores on the skin and mucus membranes. The immune system produces
antibodies against specific proteins in the skin and mucus membranes, and the
antibodies break the bonds between skin cells. This leads to the formation of a
blister. About half of sufferers first develop painful blisters and sores in the
mouth, followed by blisters on the skin that may come and go. It is 40 times
more common among Jews than in the general population of the world.
The
skin of those with pemphigus vulgaris separates easily when the surface of
unaffected skin is rubbed sideways with a cotton swab or finger. This is called
a positive Nikolsky’s sign. Severe cases of pemphigus may need wound
management, similar to the treatment for severe burns. People with this
condition may need to stay in a hospital and receive care in a burn unit or
intensive care unit.
Treatment is aimed at reducing symptoms, including
pain, and at preventing complications, especially infections. In addition to
medications, severely ill patients may undergo plasmapheresis, in which
antibody-containing plasma is removed from the blood and replaced with
intravenous fluids or donated plasma. Without treatment, this condition
is usually life threatening. Severe infection is the most frequent cause of
death. With treatment, the disorder tends to be chronic, and side effects of
treatment may be severe or disabling.
Dr. Ofer Sarig, who participated in
the research, said that since the disease is rare in general populations but
quite common among Jews, the hospital was able to provide the largest number of
participants in the genetic study. The rarity in the general population is what
delayed the discovery, added Sprecher, who is chief of dermatology at
Sourasky.
The study found that people containing the mutant gene are six
times more likely to develop pemphingus vulgaris than those lacking the
defect.
Sarig noted that with the identification of the gene, Sourasky
researchers are developing new ways to treat the disease in the future.